China
Africa
Explore chapters and articles related to this topic
Perception of Objects in the World
Published in Robert W. Proctor, Van Zandt Trisha, Human Factors in Simple and Complex Systems, 2018
Robert W. Proctor, Van Zandt Trisha
The visual system uses a number of simple cues to construct depth (Howard, 2002, 2012; Proffitt & Caudek, 2013), and most of them are summarized in Figure 6.11. Notice that while many of them are derived from the retinal image, some come from the movement of the eyes. Many depth cues are monocular, explaining why a person can see depth with a single eye. In fact, depth perception from monocular cues is so accurate that the ability of pilots to land aircraft is not degraded by patching one eye (Grosslight, Fletcher, Masterton, & Hagen, 1978), nor is the ability of young adults to drive a car (Wood & Troutbeck, 1994). Another study examined the driving practices of monocular and binocular truck drivers, and found that monocular drivers were just as safe as binocular drivers (McKnight, Shinar, & Hilburn, 1991).
Contact lenses
Published in Pablo Artal, Handbook of Visual Optics, 2017
First described in the late 1960s, one of the most common forms of contact lens correction for presbyopia used today is to correct one eye (typically the dominant eye) for distance vision, and the other (nondominant) eye for near viewing, with single vision contact lenses (Evans 2007). This technique is known as monovision, and although some binocular functions such as stereopsis are compromised over a full-distance binocular correction with reading glasses for near, research has shown that a monovision correction still provides superior binocular function over a true monocular correction, while providing visual acuity at distance and near equivalent to the patient’s corrected monocular acuity. Indeed, research interest in monovision increased significantly during the late 1980s as market demands from the aging “baby boomer” segment of the population who had grown up with contact lens correction sought an acceptable presbyopic correction. Studies demonstrated that lower levels of optical defocus in the near corrected eye impacted binocular contrast sensitivity only at the higher spatial frequencies compared to a full-distance binocular correction (Loshin et al. 1982) and that patients with added powers greater than +1.50 D started to show poorer contrast sensitivity results than a monocular distance correction (Pardhan and Gilchrist 1990). A continuous field of through-focus vision is believed to be essential for a monovision correction to be successful as it allows the visual cortex to seamlessly move from visual input of one eye to the other. Gaps in the through-focus visual field (at intermediate distances for instance) may cause difficulties for the patient to unconsciously move from the dominant eye (distance) focus to the nondominant (near) focus or vice versa. Patients with strong ocular dominance for distant and near objects in the same eye will be not be successful in monovision (Schor and Erickson 1988).
The short-term effects of artificially-impaired binocular vision on driving performance
Published in Ergonomics, 2021
Rubén Molina, Beatríz Redondo, Leandro Luigi Di Stasi, Rosario G. Anera, Jesús Vera, Raimundo Jiménez
Moreover, driving under monocular blur conditions caused drivers to have more abrupt breaking profiles, which in turn, has been linked to risky driving behaviour (Michaels et al. 2017). Furthermore, our data revealed that a sudden decline in BV functioning had a detrimental influence on driving performance, and these effects were more evident in traffic environments that make considerable visual and cognitive demands (Michaels et al. 2017) (see Figure 4). Lastly, Adrian et al. (2019) recently reported that a sudden reduction in central monocular vision with preservation of the peripheral field did not affect racing car driving performance and safety, while the opposite was true for monocular occlusion (Adrian et al. 2019). However, these results may not be comparable with our results reported here because their study was carried out during critical driving situations in a competitive context.